Donor-acceptor copolymers properties

Z.-G Zhang and J. Wang, Structures and properties of conjugated donor-acceptor copolymers for solar cell applications. Journal of Materials Chemistry, 2012. 22(10) p. 4178-4187. 

Li and coworkers [272] reported synthesis and photovoltaic properties of three donor-acceptor copolymers containing bithiazole acceptor. One of them was illustrated as follows ... 

T. Yamamoto, Z. Zhou, T. Kanbara, M. Shimura, K. Kizu, T. Maruyama, Y. Nakamura, T. Fukuda, B.-L. Lee, N. Ooba, S. Tomaru, T. Kurihara, T. Kaino, K. Kubota and S. Sasaki, n-Conjugated donor-acceptor copolymers constituted of jt-excessive and jt-deficient arylene units. Optical and electrochemical properties in relation to CT structure of the polymer, J. Am. Ghem. Soc., 118, 10389-10399 (1996). 

Chen H-Y, Hou J, Zhang S, Liang Y, Yang G, Yang Y, Yu L, Wu Y, Li G (2009) Polymer solar cells with enhanced open-circuit voltage and efficiency. Nat Photon 3 649-653 Bronstein H, Frost JM, Hadipour A, Kim Y, Nielsen CB, Ashraf RS, Rand BP, Watkins S, McCulloch 1 (2013) Effect of fluorination on the properties of a donor-acceptor copolymer for use in photovoltaic cells and transistors. Chem Mater 25 277-285... 

Beaujuge PM, Pisula W, Tsao HN, Ellinger S, Mullen K, Reynolds JR (2009) Tailoring structure-property relationships in dithienosilole-benzothiadiazole donor-acceptor copolymers. J Am Chem Soc 131 7514—7515... 

Xin H, Guo X, Kim FS, Ren G, Watson MD, Jenekhe S A (2009) Efficient solar cells based on a new phthalimide-based donor-acceptor copolymer semiconductor morphology, charge-transport, and photovoltaic properties. J Mater Chem 19 5303... 

Pandey L, Risko C, Norton JE, Bredas JL (2012) Donor-acceptor copolymers of relevance for organic photovoltaics a theoretical investigation of the impact of chemical structure modifications on the electronic and optical properties. Maaomolecules 45 6405... 

Ko S, Mondal R, Risko C, Lee JK, Hong S, McGehee MD, Bredas J-L, Bao Z (2010) Tuning the optoelectronic properties of vinylene-linked donor-acceptor copolymers for organic photovoltaics. Macromolecules 43 6685... 

Table 7.4 lists the Q and e values for an assortment of common monomers. The extremes in the column of e values in Table 7.4—which are listed in order-quantify the range of donor-acceptor properties which is used as the basis for ranking in Fig. 7.2. The Q values perform a similar ranking with respect to resonance effects. The eight different Q-e combinations in Table 7.4 allow the estimation of ri and values for 28 different copolymers. Of course, in these systems Q and e values were assigned to give the best fit to r values which had already been measured. As an illustration of the predictive values of the Q-e scheme, consider the following example ... 

Schneider HA, Cantow HJ, Percec V. (1982) Donor-acceptor complexation in macromolecu-lar systems. 1. Viscoelastic properties of polydonor-polyacceptor blends and of corresponding copolymers. Polym. Bull. (Berlin, Germany) 6 617-621. 

In Section 2.1.4, the electronic and photophysical properties of donor-acceptor or type-II heterojunctions between two semiconductor polymers were investigated. Exciplex formation was found to be a general phenomenon for type-II heterojunctions between polyfluorene copolymers. These are among the most widely used materials in polymer optoelectronics, but the presence of exciplexes had not yet been fully appreciated. This is because the exciplex population is often depopulated via efficient endothermic transfer towards the exciton, which leads to bulk exciton instead of exciplex emission. However, via time- and temperature-depen-dent photoluminescence (PL) spectroscopy the exciplex states can be identified. Employing a relationship known from small-molecule solution systems that relates the relative HOMO and LUMO levels of the molecules to the exciplex emis-... 

This chapter describes the synthesis, kinetics, and solution properties for copolymers ofN-vinylpyrrolidone (NVP) with sulfonate ionic and zwitterionic monomers. Examples of the sulfonate ionic monomers are sodium styrenesulfonate (NaSS) and sodium acrylamido-2-meth-ylpropanesulfonate (NaAMPS) an example of the zwitterionic sulfonate monomer is 2-hydroxyethyt)dimethyl(3-sulfopropyt)-ammonium inner salt, methacrylate (SPE). The NVP-NaAMPS monomer pair was exceptional, showing evidence for donor-acceptor character and an alternating tendency in copolymerization. The NVP copolymers containing simple sulfonate ionic monomers e.g., NaAMPS) showed polyelectrolyte solution properties. On the other hand, the NVP copolymers with zwitterionic sulfonate monomers showed antipoly electrolyte solution behavior. 

Y.-K. Fang, C.-L. Liu, C. Li, C.-J. Lin, R. Mezzenga, W.-C. Chen, Synthesis, Morphology, and Properties of Poly(3-Hexylthiophene)-Block-Poly(Vinylphenyl Oxadiazole) Donor-Acceptor Rod-Coil Block Copolymers and Their Memory Device Applications. Adv. Funct. Mater. 2010, 20, 3012-3024. 

J. U. Lee, A. Cirpan, T. Emrick, T. P. Russell, W H. Jo, Synthesis and Photophysical Property of Well-Defined Donor-Acceptor Diblock Copolymer Based on Regioregular poly(3-Hexylthiophene) and Fullerene. J. Mater. Chem. 2009,19,1483. 

I. Botiz, R. D. Schaller, R. Verduzco, S. B. Darling, Optoelectronic Properties and Charge Transfer in Donor-Acceptor All-Conjugated Diblock Copolymers. /. Phys. Chem. C 2011,115,9260-9266. 

Conjugated copolymers where suitable donor and acceptor segments or even blocks are chemically linked, have been demonstrated to fine tune the optoelectronic properties (e.g. bandgap, transport properties) and morphological features (e.g. phase segregation at a scale to match exciton diffusion length) to improve the optoelectronic performance and stability of related OPV devices. In particular, the donor-acceptor type alternating copolymers and donor-acceptor type block copolymers have special relevance in the context of above discussions. 

Bakhshi, A.K. and P. Bhargava. 2003. Ab initio study of the electronic structirres and conduction properties of some donor-acceptor polymers and their copolymers. J Chem Phys 119 13159. 

Yasuda, T, Y. Sakai, S. Aramaki, and T. Yamamoto. 2005. New coplanar (ABA)n-type donor-acceptor TT-conjugated copolymers constituted of alkylthiophene (unit A) and pyridazine (unit B) Synthesis using hexamethylditin, self-organized solid structure, and optical and electrochemical properties of the copolymers. Chem Mater 17 6060-6068. 

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